Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I installed a total of 36 GB of memory (4x8 GB + 2x2 GB) onn the host (Windows 7) and I used ImDisk to create a 32 GB ramdisk and formatted it with an NTFS file system.

Then I copied the virtual machine (in VMware Workstation format) folder, including .vmx, .vmdk, etc. to the newly created ram disk.

Then I tried to power it on in VMware Workstation.

What made me surprised is that the performance is not better than before. It costs almost the same time to power on the Windows 7 VM.

I checked the Resource Monitor in the Windows 7 host, and the statistics of CPU, disk and network are rather normal. The memory has reported 3000+ hard fault/sec when the guest OS boots, then drops to 0 after the guest powered on.

Any idea about this issue? I had thought the performance of ramdisk would be better than a physical disk in this case. Am I wrong?

share|improve this question
Micro optimization. Sigh. –  surfasb Apr 3 '12 at 5:03
add comment

3 Answers

My guess would be that VMWare can't handle that speed because the program is on your hard disk. You should see a performance increase (more responsive in my case) when you put the paging file on the ramdisk and make sure to make the registry edit to clear the page file at shutdown (to prevent page file error- looking for something that isn't there anymore). The page file is loaded before the ramdisk is initialized.

share|improve this answer
paging file is only used for INACTIVE applications. –  Gizmo Aug 17 '13 at 23:57
Details –  Gizmo Aug 18 '13 at 0:03
add comment

Did you check if the RAMdisk is created in virtual memory or physical memory? The virtual memory mode will use the swap file, so doing this makes no sense.

You can check this in the configuration tab of imDisk, see 'image file'. If it indicates 'virtual memory' it is created in the swap file. When you see 'Physical memory', it is created directly in memory.

Besides, the VM-files are huge, so you need to increase the block-size/cluster-size matching the VM-Drive block/cluster size.

share|improve this answer
add comment

Are you sure VMWare doesn't use the virtual disk on the physical hard drive? VMWare tends sometimes to use full paths. Rename the directory (temporarly) your VM resides in on the disk, then VMWare will present you the option to select if you moved or copied the machine, choose copied ofcourse.

After that, if it doesn't work, It could depend on VMWare's emulation properties/capabilities. You can try VirtualBox for a chage. I hope you are using SCSI instead of IDE mode in VMWare?

share|improve this answer
add comment

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.